JBD error message "barrier-based sync failed"
This document (3907838) is provided subject to the disclaimer at the end of this document.
Novell SUSE Linux Enterprise Server 9
Novell Open Enterprise Server (Linux based)
Novell SUSE Linux Enterprise Desktop 10
or, in general:JBD: barrier-based sync failed onstorage_device- disabling barriers
This message is primarily an
informational message; it does not indicate a problem.
Suppress this message globally
Please note: This method is only available for SUSE Linux Enterprise Server / Desktop (SLES/SLED) up to version 9 and for Open Enterprise Server (OES) version 1. From SLES/SLED 10 and OES2 on it is not possible to suppress the message globally. Instead use the solution in the section "Suppress this message for one filesystem".
suppress this message globally, pass the parameter
the kernel when booting (e.g., when using the GRUB boot loader,
through /boot/grub/menu.lst). This
will cause the kernel not to attempt to use the transaction barrier
Suppress this message for one filesystem
To suppress this message for one particular ext3 filesystem, use the mount option barrier=0 when mounting the filesystem.
By default, the Linux kernel will try to use transaction barriers. Transaction barriers are an additional mechanism to help maintain data integrity. In general, modern storage subsystems may cache writes and may occasionally reorder pending writes in order to increase write performance. While this is fine in general, it is not desirable when handling journal data for journaled filesystems. With journal data, metadata updates, that is updates to the journal, should be written out to the storage prior to the regular data they are associated with, to make true crash recovery possible.
The informational message indicates that the storage driver and/or the storage device do not support transaction barriers. Under normal operation, this does not compromise data integrity. However, barriers help ensure data is correctly written out to the disk.
"JBD" in this message refers to the Journaling Block Device, an abstraction that was developed to provide the journaling capabilities of the ext3 filesystem on top of the infrastructure of the ext2 filesystem on which ext3 is based. JBD is now used by the OCFS2 filesystem as well.
barrier=1 in filesystems does two independent things:
1) it prevents reordering around the barrier.
2) it causes a cache flush on the storage system. For a shared storage system with many disks this may be undesired, especially if the storage system has a battery-backed cache memory.
For more details on barrierssee TID 7003313"NFS performance drops dramatically after a SLES 10 support pack or SLES 11 install."
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- Document ID:3907838
- Creation Date:01-FEB-08
- Modified Date:08-NOV-12
- NovellOpen Enterprise Server
- SUSESUSE Linux Enterprise DesktopSUSE Linux Enterprise Server
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